You could ask him. He responds to questions. I think the PSI testing he does of the oils is fascinating and shows how oils lubricate under pressure. Regardless, I am going to switch to Amsoil 5w-30 signature Series oils in all my Mopar's.
Have you been able to find any ZDDP numbers for Amsoil Signature Series oils? Their Dominator, Z-Rod & others have high ZDDP content, but I've been under the impression that their Signature Series have considerably less because it's designed for newer vehicles with catalytic converters. Coincidentally, many have roller cams as well. Zinc & phosphorous have a negative affect on catalytic converter systems.
